change all factories to return their base-class

gm/imagefiltersgraph.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 
 #include "SkArithmeticMode.h"
@@ skipping 135 matching lines @@
             SkPaint paint;
             paint.setImageFilter(blendColor);
             DrawClippedImage(canvas, fImage, paint);
             canvas->translate(SkIntToScalar(100), 0);
         }
         {
             SkScalar matrix[20] = { SK_Scalar1, 0, 0, 0, 0,
                                     0, SK_Scalar1, 0, 0, 0,
                                     0, 0, SK_Scalar1, 0, 0,
                                     0, 0, 0, 0.5f, 0 };
-            SkAutoTUnref<SkColorMatrixFilter> matrixCF(SkColorMatrixFilter::Create(matrix));
+            SkAutoTUnref<SkColorFilter> matrixCF(SkColorMatrixFilter::Create(matrix));
             SkAutoTUnref<SkImageFilter> matrixFilter(SkColorFilterImageFilter::Create(matrixCF));
             SkAutoTUnref<SkImageFilter> offsetFilter(
                 SimpleOffsetFilter::Create(10.0f, 10.f, matrixFilter));
 
             SkAutoTUnref<SkXfermode> arith(SkArithmeticMode::Create(0, SK_Scalar1, SK_Scalar1, 0));
-            SkAutoTUnref<SkXfermodeImageFilter> arithFilter(
+            SkAutoTUnref<SkImageFilter> arithFilter(
                 SkXfermodeImageFilter::Create(arith, matrixFilter, offsetFilter));
 
             SkPaint paint;
             paint.setImageFilter(arithFilter);
             DrawClippedImage(canvas, fImage, paint);
             canvas->translate(SkIntToScalar(100), 0);
         }
         {
             SkAutoTUnref<SkImageFilter> blur(SkBlurImageFilter::Create(
               SkIntToScalar(10), SkIntToScalar(10)));
@@ skipping 38 matching lines @@
     }
 
     SkAutoTUnref<SkImage> fImage;
 
     typedef GM INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 DEF_GM(return new ImageFiltersGraphGM;)